Conventionally, there is known a speaker device including a vibrating system having a frame and a diaphragm, and a magnetic circuit system having a yoke, a magnet and a plate.
In the speaker device, the frame is formed into a bowl shape, for example. The frame having such a shape includes a magnetic circuit housing unit holding the magnetic circuit, an outer peripheral portion arranged on an outer side of the magnetic circuit housing unit and having an edge mounting part on which an outer peripheral portion of an edge is mounted, and plural arm parts connecting the magnetic circuit housing unit and the outer peripheral portion.
Examples of the frame having the configuration of this kind are disclosed in Japanese Patent Application Laid-opens under No. 6-245295, No. 2002-142290 and No. 7-95687 (hereinafter referred to as “Reference-1”, “Reference-2” and “Reference-3”, respectively). On the speaker frame according to Reference-1, a reinforcement rib is provided on each frame arm in order to improve the strength and decrease the weight. On the speaker frame according to Reference-2, a connecting part between a leg part (arm part) and the magnetic circuit mounting part, i.e., a corner part, is chamfered in order to reinforce the connection between the leg part (arm part) and the magnetic circuit mounting part and improve the strength of the speaker frame. Further, on the speaker frame according to Reference-3, the strength of the leg part connecting an edge supporting part and a magnetic circuit mounting part is inconstantly set in order to suppress divided vibration of the speaker frame.
In the above speaker device, at the time of driving thereof, the stress concentrates on the connecting part between the outer peripheral wall of the magnetic circuit housing unit and each of the arm parts on the frame. However, though the stress is different between the connecting part and a part other than the connecting part, the two parts are formed into the same shape.